Any single shareholder that owns more than 30 per cent of a company must table a bid to the other shareholders under the stock market rules.

Although Martin is not understood to be planning additional share purchases of the FTSE 250 company, the current share buyback programme is increasing his proportional piece of the pie as the number of shares in issue reduces.

The meeting will consider a "whitewash" exemption. This would increase the shareholder threshold to 35 per cent.